Current limit relay



E. N. JACOBl 1,928,334

CURRENT LIMIT RELAY Sept. 26, 1933.

2 Sheets-Sheet 1 Filed Oct. 7. 1929 P 1933- E. N. JACOB] CURRENT LIMIT RELAY Filed Oct. '7, 1929 2 Sheets-Sheet 2 'IlIIIIIlInl/unu I! N..." Ill/I ZZ/WJFLf/M 15547151.

Patented Sept. 26, 1933 UNITED STATES PATENT OFFICE Briggs and Stratton Corporation,

Milwaukee,

Wis., a corporation of Delaware Application October 7, 1929.

7 Claims.

This invention relates to certain new and useful improvements in current limit relays and refers more particularly to that type of relay adapted for use with automotive vehicles.

I Current limit relays of this type are usually mounted in back of the dash board and are designed to open a circuit upon passage of excessive current therethrough caused by a short circuit or any other similar condition.

It is an object of this invention to simplify and improve the construction of such relays.

Another object of this invention resides in the provision of a relay of the character described having toggle lever means for opening and closing the movable contactor to make it more sensitive to change in current and less likely to fail due to varying friction.

Another object of this invention resides in the provision of a relay of the character described wherein an armature imparts a hammer blow to the toggle lever means to insure opening of the circuit. 7 I

A further object of this invention resides in the provision of simplified means for resetting the 25 relay.

And a still further object of this invention is to compact a device of this type whereby it is adapted to be mounted on the back of an automotive vehicle switch or the like permitting it to be reset through the medium of the switch handle or other conveniently located actuation.

With the above andother objects in view which will appear as the description proceeds, my invention residesin the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, I have illustrated one complete example of the physical embodiment of my invention constructed according to the best mode I have so far devised for the practical application of the principles thereof, and

in which:

Figure 1 is a side elevational view of a current limit relay constructed in accordance with my inventionand illustrating the movable contactor in its closed or circuit making position;

Figure 2 is a front view thereof;

Figure 3 is a view similar to Figure 1 illustrating the-movable contactor in its open position; and

Figure 4 is a perspective view of the relay mechanism.

Serial No. 397,925

Referring now more particularly to the accompanying drawings in which like numerals designate like parts throughout the several views, the numeral 5 represents an L shaped main frame having a long substantially vertical arm 6 and a shorter substantially horizontal arm 7. The horizontal arm '7 is apertured to receive the threaded end 8 of a stud 9 whose upper enlarged end 10 extends tc, substantially the outer end of the arm 6 to provide the core of a solenoid 11. A nut 12 threaded on the end 8 of the stud cooperates with the shoulder formed by the bottom of the enlarged end 10 to clamp the stud to the arm 7 of the frame.

The solenoid may be connected in series with the circuit to be controlled, to, upon an abnormal flow of current therein, increase its magnetism to a point at which it attracts anarmature 13 to break the continuity of the circuit in the manner now about to be described.

The armature 13 is formed of a piece of magnetizable metal bent to substantially angle shape with the angle between its horizontal and vertical arms 14 and 15, respectively, slightly obtuse. A rod 16 is secured to the arm 15 adjacent its upper end to provide a pivotal mounting for the armature by having its ends received in apertures formed in ears 1'? extended from the adjacent upper end of the main frame arm 6. Under normal conditions, the armature is maintained in its open or inoperative position illustrated in Figures 1 and 2 by a spring 18 fixed at its lower end to the main frame 5 in a manner to be later described and which its free end engaging the arm 15 of the armature, the spring being sufficiently strong to restrain movement of the armature until the current flowing through the solenoid exceeds a predetermined value.

The position of the armature governs the position of a movable contactor 19. When the armature is in its normal position the contactor 19 engages and electrically bridges a pair of stationary contacts 26, and when attracted to the solenoid it moves the contactor out of engagement with the stationary contacts to its position illustrated in Figure 3.

The movable contactor 19 comprises a pair of terminals 21 formed by the heads of rivets which secure a metal connecting strip 22 to a block of insulating material 23. The block 23 provides insulating means for mounting the contactor and is secured, by rivets 24, to the transverse portion 25 of a substantially U shaped lever 26 having side arms 27 which are pivotally connected at their upper ends, by a pin 28, with a second. substantially U shaped lever 29 to form a toggle device maintaining the movable contactor in either of its positions and providing means for quickly moving it from one position to the other.

The second substantially U shaped lever 29 has its transverse portion 30, which extends across the width of the main frame, offset to be spaced therefrom sufiiciently to over-lie the adjacent end 31 of the armature arm 15, and is pivotally mounted from the main frame by a pin 33 extending through aligned apertures in the upper ends of its side arms 32 and cars 34 of a bracket member fixed to the adjacent upper end of the main frame. A contractile spring 35 having one end connected with the pin 33 and its other end connected with a pin 36 extending across the-side arms 27 of the lower lever 26, serves to maintain the outer free end of the lever 26 which carries a contactor 19 to one side or the other of an imaginary line drawn through the axis of the pins 28 and 33.

To prevent the collapse of the toggle the transverse portion 30 of the lever 29 has a stop member or foot 3'7 extended therefrom to engage the adjacent outer face of the main frame 5 and prevent inward movement of the lever 29. The foot 3'7 is positioned at one side of the transverse portion 30 and as best illustrated in Figure 2, the armature arm 15 is cut away at one side to permit the foot 3'7 to pass and engage the main frame.

The stationary contacts 20 are preferably formed of spring metal and are fixed at their upper ends to the adjacent lower portion of the main frame by screws 38 or the like, being insulated therefrom by a strip of insulating material 39 positioned between the frame and the contacts. Terminals 40, one for each stationary contact and with a portion thereof directly engaging the upper ends of the contacts, are mounted by the screws 38, which also pass through the lower portion of the spring 18 to mount the same, insulating washers 41 being positioned between the attaching portions of the terminals 40 and spring 18 to provide the necessary insulation.

As best illustrated in Figure l, the end 31 of the armature arm 15 which is positioned beneath the transverse portion 30 of the lever 29, is slightly spaced therefrom when in its normal position so that upon movement of the armature toward the solenoid, a hammer blow will be imparted to the transverse portion of the lever 29, to carry the free end of the lever and consequently the point of pivot 28 outwardly beyond an imaginary line drawn through the axis of the pins 33 and 36. This permits the energy of the spring 35 to snap the movable contactor 19 out of engagement with the contacts 20 to break the circuit, the movement of the movable contactor by the spring 35 being limited upon engagement with a member 42 threaded on the stud 9 beneath the nut 12.

To permit the resetting of the relay after the occurrence of an overload, the lever 29 is provided with an arm 43, to the outer end of which a wire 44 or the like is secured to lead to a convenient position on the dash of the vehicle, not shown, with which the relay is used, so that it is only necessary to exert a pull on the wire 44 to restore the elements of the relay to their original positions.

From the foregoing description taken in con- 'nection with the accompanying drawings, it will.

be readily apparent to those skilled in the art to which an invention of the character described appertains, that I provide a simplified construction for current limit relays wherein the opening of the circuit upon an overload is positive, being assured by a hammer blow action of the armature and wherein a toggle arrangement insures the maintaining of the movable contactor in either of its positions.

What I claim as my invention is:

1. A device of the character described, comprising a substantially L shaped frame, a solenoid carried by one arm of said frame and spaced from the other arm thereof, a substantially right angular armature pivotally mounted from the frame with one arm overlying the frame and the other arm in operative relation to the solenoid, a stationary contact carried by the frame, a toggle device comprising pivotally connected members mounted from the main frame between it and the solenoid, a movable contactor carried by one member of said toggle device and engageable with the stationary contact, and means carried by the toggle device and engageable by the armature arm overlying the frame, whereby movement of the armature moves the toggle device to disengage the contactor from the contact.

2. A device of the character described, comprising a substantially L shaped frame, a solenoid carried by one arm of the said frame and spaced from the other arm thereof, a substantially L :laped armature, means pivotally mounting the armature at its apex from the free end of said second mentioned main frame arm whereby one arm of the armature is positioned along the outer face of said main frame arm and the other arm of the armature is disposed in operative relation to the solenoid, a stationary contact carried by the main frame, a movable contactor engageable therewith, a toggle device mounting the movable contactor and disposed between the solenoid and the main frame arm mounting the armature, and means carried by the toggle device and extending over the armature arm overlying the main frame, whereby movement of the armature upon energization of the solenoid moves the toggle device to move the movable contactor with respect to the stationary contact.

3. A device of the character described comprising an elongated frame having a laterally directed arm, a solenoid mounted on said arm and spaced from the frame, a substantially angular shaped armature, means pivotally mounting the armature from the free end of the frame whereby one of its arms overlies the outer face of the frame and its other arm is disposed in operative relation to the solenoid, a stationary contact carried by the frame, a movable contactor en gageable therewith, a toggle device disposed in the space between the main frame and the solenoid and comprising a member pivotally mounted from the free end of the frame, a second member connected with the first member and by which the movable contactor is carried, spring means connecting the members at points on opposite sides of their pivotal connection, and means carried by the first member and with which the armature arm overlying the main frame engages upon energization of the solenoid to move said first member to a position causing the spring means to snap the other member and consequently the movable contactor to circuit breaking position.

4. In a current limit relay of the character described, an L-shaped frame having a pair of legs at right angles, a solenoid mounted on one of said legs and extending parallel to the other leg, a substantially L-shaped armature connected adjacent the apex thereof to the outer end of the second leg,,and having one arm thereof overlying said second leg and the other arm thereof in operative relation with said solenoid, a toggle joint pivotally mounted from said second leg adjacent the outer end thereof and lying between said second leg and said solenoid, means formed integrally on one link of said joint engageable with said overlying arm to actuate said toggle, means on said last named means to limit the movement of said toggle in one direction, a stationary contact mounted on said frame and a movable contact carried by a second link of said toggle.

5. In a current limit relay of the character I described, an L-shaped frame having a pair of legs at right angles, a solenoid mounted on one of said legs and extending parallel to the other leg, 21. substantially L-shaped armature connected adjacent the apex thereof to the outer end of the second leg, and having one arm thereof overlying said second leg and the other arm thereof in operative relation with said solenoid, a toggle joint pivotally mounted from said second leg adjacent the outer end thereof and lying between said second leg and said solenoid, means formed integrally on one link of said joint engageable with said overlying arm to actuate said toggle, a stationary contact mounted on said frame and a movable contact carried by a second link of said toggle.

6. In a current limit relay of the character described, an L-shaped frame having a pair of legs at right angles, a solenoid mounted on one of said legs and extending parallel to the other leg, a substantially L-shaped armature connected adjacent the apex thereof to theouter end of the second leg, and having one arm thereof overlying said second leg and the other arm thereof in operative relation with said solenoid, a toggle joint pivotally mounted from said second leg adjacent the outer end thereof and lying between said second leg and said solenoid, means formed integrally on one link of said joint engageable with said overlying arm to actuate said toggle, means on said last named means cooperating with said frame to limit the movement of the central joint of said toggle inwardly, a stationary contact mounted on said frame and a movable contact carried by a second link of said toggle.

'7. In a current limit relay of the character described, an L-shaped frame having a pair of legs at right angles, a solenoid mounted on one of said legs and extending parallel to the other leg, a substantially L-shaped armature connected adjacent the apex thereof to the outer end of the second leg, and having one arm thereof overlying said second leg and the other arm thereof in operative relation with said solenoid, a toggle joint pivotally mounted from said second leg adjacent the outer end thereof and lying between said second leg and said solenoid, means formed integrally on one link of said joint engageable with said overlying arm to actuate said toggle, means on said last named means to limit the movement of said toggle in one direction, a stationary contact mounted on said frame, a movable contact carried by a second link of said toggle, and means formed on a portion of said stationary contact constantly urging said first arm of said armature out of engagement with said solenoid.

EDWARD N. JACOBI. 

